Specifying and Executing the Combination of Timed Finite State Automata and Causal-Block Diagrams by Mapping Onto Devs.

Multi-Paradigm Modeling (MPM) advocates to explicitly model every part and aspect of a system, at the most appropriate level(s) of abstraction, using most appropriate formalism(s). We show, starting from a representative Personalized Rapid Transportation rail car example, how MPM naturally leads to the need to combine formalisms. To give these formalisms a precise semantics and to make them executable, we choose to map them all onto behaviorally equivalent (modulo some level of approximation in the case of continuous formalisms) Discrete EVent system Specification (DEVS) models. Our focus and main contribution is the principled combination TFSA>(CBD+StEL) of Timed Finite State Automata (TFSA) and Causal Block Diagrams (CBDs) using a State Event Location “glue” formalism StEL, and their mapping onto DEVS. The result of our principled workflow, explicitly modeled in a Formalism Transformation Graph + Process Model (FTG+PM) is an accurate and efficient simulator. This is demonstrated on the rail car case.